U.S. patent application number 11/321004 was filed with the patent office on 2007-06-28 for photographing apparatus, image display method, computer program and storage medium.
Invention is credited to Hiroyasu Nose.
Application Number | 20070146530 11/321004 |
Document ID | / |
Family ID | 38193157 |
Filed Date | 2007-06-28 |
United States Patent
Application |
20070146530 |
Kind Code |
A1 |
Nose; Hiroyasu |
June 28, 2007 |
Photographing apparatus, image display method, computer program and
storage medium
Abstract
A photographing apparatus comprises a plurality of optical image
pickup units which converges object light and forming an optical
image on a focus plane of an image pickup device and an image
forming unit which forms a plurality of photographed images from
optical images formed by the optical image pickup units. The
optical axes of the optical image pickup units cross at one point
near lenses, the optical image pickup units are disposed at an
equal distance from the cross point, and the optical axes are set
at a predetermined angle in such a manner that photographing fields
of adjacent optical image pickup units are made contiguous with
each other.
Inventors: |
Nose; Hiroyasu; (Tokyo,
JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
3 WORLD FINANCIAL CENTER
NEW YORK
NY
10281-2101
US
|
Family ID: |
38193157 |
Appl. No.: |
11/321004 |
Filed: |
December 28, 2005 |
Current U.S.
Class: |
348/335 |
Current CPC
Class: |
G03B 37/04 20130101 |
Class at
Publication: |
348/335 |
International
Class: |
G02B 13/16 20060101
G02B013/16 |
Claims
1. A photographing apparatus comprising: a plurality of optical
image pickup units adapted converge object light and forming an
optical image on a focus plane of an image pickup device; and an
image forming unit adapted to form a plurality of photographed
images from optical images formed by said optical image pickup
units, wherein optical axes of said optical image pickup units
cross at one point near lenses, said optical image pickup units are
disposed at an equal distance from the cross point, and the optical
axes are set at a predetermined angle in such a manner that
photographing fields of adjacent optical image pickup units are
made contiguous with each other.
2. The photographing apparatus according to claim 1, wherein said
optical image pickup units are disposed in a lattice form, optical
axes of said optical image pickup units cross at one point on an
object side, and said optical image pickup units are disposed at an
equal distance from the cross point.
3. The photographing apparatus according to claim 1, wherein said
optical image pickup units are disposed in such a manner that an
overlap area having a width substantially equal to a distance
between principal points of adjacent optical image pickup units on
an object side is formed in a joining portion of photographing
field angles of the adjacent optical image pickup units.
4. The photographing apparatus according to claim 1, further
comprising: an optical filter disposed near the cross point of the
optical axes of said optical image pickup units to guide object
light to each of said optical image pickup units via said optical
filter; and a switching unit adapted switch said optical
filter.
5. The photographing apparatus according to claim 4, wherein said
optical filter is an infrared cut filter.
6. The photographing apparatus according to claim 1, further
comprising: an image signal processing unit adapted to process an
image signal output from said optical image pickup devices; an
image encoding unit adapted encode image pickup data processed by
said image signal processing unit; and a communication control unit
adapted transmit said image pickup data.
7. The photographing apparatus according to claim 1, wherein said
image forming unit generates a plurality of images of an object at
a position behind the cross point of the optical axes of said
optical image pickup units.
8. A photographing system comprising a photographing apparatus and
a monitor apparatus, wherein said photographing apparatus
comprises: a plurality of optical image pickup units adapted to
converge object light and forming an optical image on a focus plane
of an image pickup device, said optical image pickup units being
disposed at an equal distance from one point near lenses at which
optical axes of said optical image pickup units cross, and the
optical axes being set at a predetermined angle in such a manner
that photographing fields of adjacent optical image pickup units
are made contiguous with each other; an image signal processing
unit adapted to process an image signal output from said optical
image pickup devices; an image encoding unit adapted to encode
image pickup data processed by said image signal processing unit;
and a communication control unit adapted transmit said image pickup
data; and wherein said monitor apparatus comprises a display unit
adapted to display image pickup data output from said photographing
apparatus and transmitted from said communication control unit.
9. An image display method of displaying image pickup data received
from a photographing apparatus comprising a plurality of optical
image pickup units adapted to converge object light and forming an
optical image on a focus plane of an image pickup device, said
optical image pickup units being disposed at an equal distance from
one point near lenses at which optical axes of said optical image
pickup units cross, and the optical axes being set at a
predetermined angle in such a manner that photographing fields of
adjacent optical image pickup units are made contiguous with each
other, the image display method comprising steps of: displaying
images of the image pickup data received from said optical image
pickup units on a window of a display unit at predetermined
positions; and changing a joining position of adjacent images on
the window to a desired position.
10. The image display method according to claim 9, further
comprising a step of storing information on said joining
position.
11. A computer-readable program for causing a computer to execute
an image display process of displaying image pickup data received
from a photographing apparatus comprising a plurality of optical
image pickup units adapted to converge object light and forming an
optical image on a focus plane of an image pickup device, said
optical image pickup units being disposed at an equal distance from
one point near lenses at which optical axes of said optical image
pickup units cross, and the optical axes being set at a
predetermined angle in such a manner that photographing fields of
adjacent optical image pickup units are made contiguous with each
other, the program comprising: a process of displaying images of
the image pickup data received from said optical image pickup units
on a window of a display unit at predetermined positions; and a
process of changing a joining position of adjacent images on the
window to a desired position.
12. A recording medium computer-readably recording a computer
program for causing a computer to execute an image display process
of displaying image pickup data received from a photographing
apparatus comprising a plurality of optical image pickup units
adapted to converge object light and forming an optical image on a
focus plane of an image pickup device, said optical image pickup
units being disposed at an equal distance from one point near
lenses at which optical axes of said optical image pickup units
cross, and the optical axes being set at a predetermined angle in
such a manner that photographing fields of adjacent optical image
pickup units are made contiguous with each other, the computer
program comprising: a process of displaying images of the image
pickup data received from said optical image pickup units on a
window of a display unit at predetermined positions; and a process
of changing a joining position of adjacent images on the window to
a desired position.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to technologies for acquiring
a photographed image in a wide range by using a photographing
apparatus.
[0003] 2. Related Background Art
[0004] A wide-angle photographing apparatus is known which can
acquire a photographed image in a wide range by combining
photographed images taken with a plurality of optical photographic
systems. For example, this wide-angle photographing apparatus is
applied to a monitor camera, a television conference camera and the
like.
[0005] For a wide range photographing system, a method has been
proposed by which a plurality of cameras are disposed radially as
shown in FIG. 10 and photographed images taken with the cameras are
joined together to realize paronama photographing. A camera 1 is
disposed on each side of a polygonal housing 101 to photograph each
divided area of a photographing range of 360.degree.. The system of
this kind is disclosed, for example, in Japanese Patent Application
Laid-open Nos. H07-067020, H09-093471, No. 2001-204015 and the
like.
[0006] Another system has also been proposed in which a hyperbolic
mirror is used to photograph a whole peripheral area as shown in
FIG. 11. One camera is disposed under a hyperbolic mirror 102 and a
whole peripheral image is focussed on an image pickup device of the
camera 1. An image focussed on the image pickup device will be
described with reference to FIG. 12. In FIG. 12, an image in a
whole peripheral area is focussed on a ring area 104 of an image
pickup device 103. When the image is displayed on a monitor or the
like, image processing is performed by an unrepresented processor
circuit to convert the image in a laterally elongated panorama
image. The system of this type is disclosed, for example, in
Japanese Patent Application Laid-open No. H06-295333 and Japanese
Patent Publication No. H09-505447 and the like.
[0007] A conventional system in which a plurality of cameras are
disposed radially will be described with reference to FIG. 13.
[0008] In FIG. 13, three cameras 11, 12 and 13 are disposed
radially to realize wide-angle photographing. The camera 11 is
constituted of a photographing lens 2, an image pickup device 4
such as CCD and CMOS and a substrate 6, and a sector photographing
field angle having a center at the principal point of the lens 2 on
the object side is focussed on the image pickup device 4. The
structure of the cameras 12 and 13 is similar to that of the camera
11, and the cameras are disposed so that the photograph field
angles are overlapped. With the photographic field angles of the
cameras 11 and 12, an object in the oblique line area surrounded by
field angle boundaries 21 and 22 and their cross point 20 is taken
into both the photographed images of the cameras 11 and 12.
[0009] Ideally, as shown in FIG. 14, if the principal point 3 of
each camera on the object side is made coincident, an image taken
with each camera has no parallax so that the images are contiguous
with each other at each joining point and it is easy to join the
images smoothly. However, in practice, each camera has a physical
size and is interfered with each other. It is therefore difficult
to dispose the cameras in such a manner that the principal points
on the object side become coincident. From this reason, the radial
layout such as shown in FIG. 13 has been used conventionally.
Therefore, the principal points of adjacent cameras on the object
side are spaced apart by a distance L shown in FIG. 13 (hereinafter
this distance L is called a base line length).
[0010] With this layout, photographed images taken with adjacent
cameras have a larger parallax difference as the base line length L
becomes longer. Therefore, in an area where the joining portions
are overlapped, the positions of an object in the adjacent
photographed images differ considerably and the images in the
joining portions are not coincident. It is therefore difficult to
join the two images smoothly.
[0011] With reference to FIG. 15, description will be made on how
an object is photographed in an area where the photographing field
angles of adjacent cameras are overlapped. A nearest distance
between the photographing ranges of cameras 11 and 12 is
represented by S1. It is assumed that the cameras are disposed in
such a manner that the boundary 21 of the photographing field angle
of the camera 11 crosses the boundary 22 of the photographing field
angle of the camera 12, at a cross point 20 at the nearest distance
S1.
[0012] The photographed images to be taken with the cameras 11 and
12 are focused via lenses on the image pickup devices. The
photographed images do not change even if it is virtually assumed
that the image pickup plane exists on the object side with respect
to the lens. Description will be made therefore assuming that the
image pickup planes are at 23 and 24. An object 25 (white circle
symbol) at the cross point 20 of the nearest distance S1 is
photographed on the boundary between the image pickup planes 23 and
24 of the cameras 11 and 12. FIG. 16 shows that the photographed
images 201 and 202 taken with the cameras 11 and 12 are juxtaposed
in contact with each other. As shown in FIG. 16, an image 25a of
the object 25 (white circle symbol) is photographed generally in
unison on the boundary between the photographed images 201 and
202.
[0013] In FIG. 15, an object 26 (black triangle symbol) at a
photographing distance S2 on the boundary 22 of the camera 12 is
projected on the image pickup plane 23 of the camera 11 as
indicated by an arrow in FIG. 15. Although not shown on the image
pickup plane 24 of the camera 12, an object is projected on the
boundary similar to the object 25. Therefore, in the photographed
images shown in FIG. 16, although the photographed image 202 of the
object 26 (black triangle symbol) is projected on the boundary as
an image 26a, the photographed image 201 is projected as an image
26b shifted from the boundary. A shift amount 206 of the images
taken with the cameras 11 and 12 is called a parallax amount.
[0014] An object 27 (white square symbol) at a infinite distance S3
on the boundary 22 of the camera 12 is projected on the image
pickup plane 23 of the camera 11 at a position on a line parallel
to the boundary 22 corresponding to the base line length L, as
shown in FIG. 15. The object 27 is projected on the image pickup
plane 24 of the camera 12 at the boundary similar to the objects 25
and 26. Therefore, in the photographed images shown in FIG. 16, the
object 27 (white square symbol) at the infinite distance is
photographed on the boundary as an image 27a in the photographed
image 202, whereas it is photographed as an image 27b on a dotted
line 204 in the photographed image 201. As the distance of an
object becomes longer, a parallax amount 206 increases. The object
at an infinite distance has a constant converged parallax amount
represented by a distance between the dotted line 204 and the
boundary 203 between the photographed images 201 and 201.
[0015] The foregoing description concerns about the object on the
boundary 22 of the photographing field angle of the camera 12.
Similar description can be made also for an object on the boundary
21 of the photographing field angle of the camera 11. Namely, as
the parallax amount increases as the object distance becomes long,
an object at an infinite distance is projected as an image on a
dotted line 205 in the photographed image 202. An object in an area
where the photographing field angles of the cameras 11 and 12 are
overlapped, is duplicately photographed depending upon an object
distance in the area sandwiched between the dotted lines 204 and
205, resulting in a parallax.
[0016] A parallax amount of an object at an infinite distance
becomes large in proportion to the base line length L of the
cameras 11 and 12. Therefore, if the base line length L is long,
although the photographed images taken with the cameras 11 and 12
are coincident for an object at the nearest distance on the
boundary, a parallax amount of an object at the infinite distance
becomes large so that the photographed images are not coincident
and smooth joining cannot be realized.
[0017] With such a radial layout, even if the cameras are disposed
so as to shorten the base line length, the image pickup device
substrates 6 of the cameras interfere with each other so that the
lens front ends are made open. Therefore, the base line length L
becomes long, a parallax difference between images taken with
adjacent cameras becomes large, and it is difficult to connect the
images at the joining portion without suppressing contradiction.
Since the front ends of the cameras are made radially open, the
camera lens layout becomes conspicuous and it is difficult to make
compact the whole housing of a camera.
[0018] In a system using a hyperbolic mirror, an object image is
focussed as a distorted image on the image pickup device, and
converted into a normal image by image processing. Therefore, the
pixel density of an image after conversion is not uniform over the
whole area so that a portion greatly enlarged has coarse pixels and
its image quality is degraded. There are less cases in which an
image in a whole circumferential area becomes necessary for an
application to a monitor camera and the like. If the monitor camera
is mounted on a wall or the like, it is sufficient if the
photographing field angle is about 120.degree. to 180.degree. in
the horizontal direction. A monitor camera providing an image
having a high resolution in this field angle range is desired. Such
needs cannot be satisfied by a hyperbolic mirror system.
[0019] In a modeling system for generating a shape model of an
existing substance described in Japanese Patent Application
Laid-open No. H11-328444, a main camera and subsidiary cameras are
disposed radially about a Z-axis, and their viewpoints (light
reception axes) are set so that the viewpoints cross at one point
(e.g., coordinate origin) on the Z-axis.
[0020] In a synchronous photographing method and system described
in Japanese Patent Application Laid-open No. 2002-344800, three
digital two-lens cameras each having two pairs of photographing
units are used, and one camera is disposed just in front of the
face of an object person, and the other two cameras are disposed at
right and left positions slightly lower than the face.
SUMMARY OF THE INVENTION
[0021] The present invention solves the above-described problems
and aims to provide a photographing apparatus capable of making
compact a photographing unit and reducing a parallax of a plurality
of photographed images, an image display method, a computer program
and a storage medium.
[0022] As a means for achieving the object, the present invention
provides a photographing apparatus which comprises: a plurality of
optical image pickup units for converging object light and forming
an optical image on a focus plane of an image pickup device; and an
image forming unit for forming a plurality of photographed images
from optical images formed by the optical image pickup units,
wherein optical axes of the optical image pickup units cross at one
point near lenses, the optical image pickup units are disposed at
an equal distance from the cross point, and the optical axes are
set at a predetermined angle in such a manner that photographing
fields of adjacent optical image pickup units are made contiguous
with each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The above-described object of the present invention becomes
apparent from the following drawings and the detailed description
when read in conjunction with the drawings.
[0024] FIG. 1 is a diagram showing the outline structure of a
wide-angle photographing apparatus according to a first embodiment
of the present invention.
[0025] FIG. 2 is a diagram showing an example of a camera layout of
the wide-angle photographing apparatus according to the first
embodiment of the present invention.
[0026] FIGS. 3A and 3B are diagrams showing photographed images
taken with cameras.
[0027] FIG. 4 is a diagram showing examples of photographed images
on a monitor of the wide-angle photographing apparatus according to
the first embodiment of the present invention.
[0028] FIG. 5 is a flow chart illustrating a control program for
the wide-angle photographing apparatus according to the first
embodiment of the present invention.
[0029] FIG. 6 is an illustrative diagram showing a wide
angle-photographing apparatus according to a modification of the
first embodiment of the present invention.
[0030] FIG. 7 is a diagram showing an example of a camera layout of
a wide-angle photographing apparatus according to a second
embodiment of the present invention.
[0031] FIGS. 8A, 8B and 8C are a front view and cross sectional
views showing a camera layout of the wide-angle photographing
apparatus according to the second embodiment of the present
invention.
[0032] FIG. 9 is a diagram showing the outline structure of a
wide-angle photographing apparatus according to a third embodiment
of the present invention.
[0033] FIG. 10 is a diagram showing a conventional wide-angle
photographing apparatus having cameras disposed radially.
[0034] FIG. 11 is a diagram a conventional wide-angle photographing
apparatus using a hyperbolic mirror.
[0035] FIG. 12 is a diagram showing a photographed image on an
image pickup device of the conventional wide-angle photographing
apparatus having the hyperbolic mirror.
[0036] FIG. 13 is a diagram showing a camera layout of a
conventional photographing apparatus having cameras disposed
radially.
[0037] FIG. 14 is a diagram showing an ideal camera layout of a
conventional photographing apparatus having cameras disposed
radially.
[0038] FIG. 15 is a diagram showing photographed images taken with
a conventional wide-angle photographing apparatus having cameras
disposed radially.
[0039] FIG. 16 is a diagram illustrating the state of a joining
portion of photographed images taken with a conventional wide-angle
photographing apparatus having cameras disposed radially.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0040] Embodiments of the present invention will be described with
reference to the accompanying drawings.
First Embodiment
[0041] FIG. 1 is a block diagram showing the outline structure of a
wide-angle photographing apparatus according to an embodiment of
the present invention. In FIG. 1, a housing 30 of the wide-angle
photographing apparatus accommodates cameras 11, 12 and 13 each
constituted of a lens and an image pickup device, and a camera
drive control circuit. Each of the cameras 11, 12 and 13 uses a
single focus lens, and optical axes 14, 15 and 16 of the cameras
are disposed in such a manner that the optical axes cross at a
cross point of each lens on an object side.
[0042] A lens capable of being in-focus from a near field to a far
field through pan focussing may be used for the camera.
Alternatively a lens capable of being automatically set in-focus
through auto focussing may be used. In this case, if focusses of
three cameras are different, focus points of images of a panorama
display are different and the images are difficult to be clearly
observed. Therefore, one camera which mainly photographs an object
is designated, and the focuses of the other two cameras are
controlled to follow the focus of the designated camera.
[0043] If automatic exposure adjustments of the three cameras are
different, brightness of each image in a panorama display becomes
different and the images cannot be viewed contiguous with each
other. Therefore, one camera which mainly photographs an object is
designated, and the exposure adjustment values of the other two
cameras are controlled to be follow the exposure adjustment value
of the designated camera.
[0044] Next, with reference to FIG. 2, detailed description will be
made on the layout of the cameras according to the present
invention. The cameras 11, 12 and 13 are disposed in such a manner
that the optical axes of the cameras 11, 12 and 13 cross at a cross
point 5 of the lenses on the object side, and that the photographic
field angle of each camera crosses at the cross point 5 to allow
each camera to photograph an image in each divided wide-angle
photographing area. Adjacent cameras are disposed by making the
lens front ends become near to each other as much as possible and
minimizing the distance (base line length) L between principal
points 3 on the object side. The adjacent cameras 11 and 12 are
disposed in such a manner that a boundary 21 of a photographing
field angle 17 of the camera 11 and a boundary 22 of a
photographing field angle 18 of the camera 12 overlap each other by
the same width equal to the base line length L, as shown in FIG. 2.
The boundaries of the cameras 12 and 13 are disposed overlapping in
a similar manner.
[0045] With reference to FIG. 2 and FIGS. 3A and 3B, description
will be made on how objects in an overlapped area of the
photographic field angles of the cameras 11 and 12 are photographed
by each camera. In FIG. 2, assuming that the image pickup planes
are on an object side, even if the photographed images of the
cameras 11 and 12 are projected, the photographing relation will
not change. Therefore, in the following description, it is assumed
that the image pickup planes are at positions 23 and 24.
Description will be made on how an object 26 (solid black triangle
symbol) and an object 27 (square symbol) are photographed, the
object 26 being on the boundary 21 at a photographing distance S1
and the object 22 being on the boundary 21 at an infinite distance
S3, as referenced to an object 25 (circle symbol) on the boundary
21 at the nearest distance S1.
[0046] FIG. 3A shows photographed images 201 and 202 on the image
pickup planes of the cameras 11 and 12, the images being juxtaposed
in contact with each other. In the photographed image 202 of the
camera 12, the object 25 (circle symbol) at the nearest distance S
is projected as an image 25a on the boundary, whereas in the
photographed image 201 of the camera 11, it is projected as an
image 25b. A parallax 206 appears therefore and the object is
duplicately photographed.
[0047] Similarly, in the photographed image 202 of the camera 12,
the object 26 (solid black triangle symbol) at the photographing
distance S2 is projected as an image 26a on the boundary, whereas
in the photographed image 201 of the camera 11, it is projected as
an image 26b. A parallax amount is smaller than that of the object
27 (square symbol). In the photographed image 202 of the camera 12,
the object 27 (square symbol) at the infinite distance S3 is
projected as an image 27a on the boundary, whereas in the
photographed image 201 of the camera 11, it is projected as the
image 27a on the boundary. The image is coincident on the
boundary.
[0048] As above, the object in the overlapped area of the
photographic field angles of the cameras 11 and 12 at the nearest
distance S1 is duplicately photographed in an area sandwitched
between a dotted line 204 of the photographed image 201 and a
dotted line 205 of the photographed image 202, with the parallax
206. As the positions of the object become farther from the nearest
distance S1, the parallax 206 becomes smaller, and the object at
the infinite distance is photographed as the same image on the
boundary 203 of the photographed images 201 and 202.
[0049] The area sandwiched between the dotted line 204 of the
photographed image 201 and the dotted line 205 of the photographed
image 202 becomes broader in proportion to the base line length L
of the cameras 11 and 12. Therefore, as in the embodiment, if the
cameras 11 and 12 can be disposed at a shorter base line length L,
the area where an image near the boundary between the photographed
images is photographed duplicately can be narrowed and a parallax
amount of images can be made small. Therefore, even if the
photographed images are joined at the boundary, contradiction in
the joining portion can be made not conspicuous.
[0050] Referring back to FIG. 1, the overall structure of the
wide-angle photographing apparatus will be described. In FIG. 1,
A/D convertor circuits 31, 32 and 33 convert video signals output
from image pickup devices 4 of the cameras 11, 12 and 13 into
digital signals. An image signal processing circuit 34 receives
outputs from the A/D convertor circuits 31, 32 and 33, and executes
a pixel interpolation process and a color conversion process to
output image pickup data.
[0051] A memory control circuit 35 controls the A/D convertor
circuits 31, 32 and 33, image signal processing circuit 34 and a
memory 36 for acquisition, storage and the like of image pickup
data. The memory 36 is a volatile memory or a non-volatile memory.
The memory stores temporarily image pickup data, and can be used as
a storage area for programs of controlling a system controller 37
and a working area for the system controller 37.
[0052] An image encoding circuit 39 compression-encodes image
pickup data by an encoding scheme such as JPEG. A communication
control circuit 38 transmits/receives image pickup data,
photographing control data and the like. An internal bus 40 is used
for transferring image pickup data and various control signals. The
system controller 37 controls the whole apparatus by controlling
the memory control circuit 35, image encoding circuit 39 and
communication control circuit 38 via the internal bus 40.
[0053] Image pickup data is transferred via a network line 41 to a
monitor apparatus constituted of a personal computer 42 and a
monitor 43 installed at a remote site, so that a view image of the
image pickup data can be displayed on the monitor 43.
[0054] Next, description will be made on the operation of the
wide-angle photographing apparatus constructed as above. Referring
to FIG. 1, video signals obtained by synchronously photographing of
the cameras 11, 12 and 13 are converted into digital image pickup
data by the A/D convertor circuits 31, 32 and 33. Digitalized image
pickup data of the cameras is processed in parallel by the image
signal encoding circuit 34 which executes the pixel interpolation
process and color conversion process. The processed image pickup
data is temporarily stored in the memory 36 on the video image
frame basis by the memory control circuit 35. In this case, the
encoded image pickup data of the cameras 11, 12 and 13 is added
with an identification number of the wide-angle photographing
apparatus and an identification number capable of identifying each
camera of the wide-angle photographing apparatus.
[0055] Next, the image encoding circuit 39 sequentially encodes the
video image frames of the image pickup data of the cameras 11, 12
and 13. The encoded image pickup data is sent to the communication
control circuit 38 and delivered to the network line 41. For
example, the network is the Internet using the TCP/IP protocol. The
personal computer 42 receives the encoded image pickup data,
executes a decoding process by using a control program for the
wide-angle photographing apparatus installed in the personal
computer 42, and displays photographed images on the monitor
43.
[0056] FIG. 4 is a diagram showing a display example of
photographed images on the monitor 43 according to the embodiment.
The control program displays an image display window 51 on a screen
50 of the monitor 43. In the frame of the window, photographed
images 201, 202 and 203 of the cameras 11, 12 and 13 are displayed
in contact with each other as a panorama image. An object in the
near field is duplicately displayed in the area sandwitched between
dotted lines 204 and 205 near the boundary of the photographed
images 201 and 202. However, a width of this area is narrow because
the cameras 11 and 12 are disposed at a shorter base line length L,
and a parallax amount of the object is also small. Therefore, as
the photographed images are actually observed, the images can be
viewed in a contiguous state and substantially a panorama image can
be viewed.
[0057] The image display window 51 shown in FIG. 4 has an
adjustment button 52 for finely adjusting the position of the
photographed image 201 visually by an observer by using the
photographed image 202 as a reference. The boundary position
between the photographed images can be adjusted in a horizontal
direction by using horizontal direction keys of the adjustment
button 52.
[0058] For example, if an object to be observed is in a relatively
near field and an importance of an image of a far scene is low, the
adjustment is made in the manner shown in FIG. 3B. Namely, the
image is moved to partially cut the area near the boundary of the
photographed images 201 and 202 in such a manner that the images
26a and 26b of the object in the near field to be observed are
combined to one image on the boundary of the photographed images
201 and 202. By combining the images in this manner, although the
image of a far scene is partially lost, the object to be observed
will not be displayed duplicately and the photographed images are
displayed seamlessly. Similarly, for the photographed images 202
and 203 shown in FIG. 4, the boundary position of the photographed
image is adjusted by an adjustment button 53 by using the
photographed image 202 as a reference. The image of an object to be
observed can be viewed more seamlessly.
[0059] The adjustment buttons 52 and 53 are configured so that the
positions of the photographed images 201 and 203 in the vertical
direction can be adjusted. It is possible to correct a shift of a
photographed image in the vertical direction to be caused by an
error of the camera layout, a displacement of an optical axis and
the like. Namely, an adjustment amount of each boundary position of
photographed images designated by the adjustment buttons is stored
in accordance with the control program. The control program is once
terminated and when the images are displayed next time, the
adjustment amount of each boundary position of the photographed
images is read to automatically set the adjustment amount to the
image display window.
[0060] A series of operations of the wide-angle photographing
apparatus is controlled by the control program in the personal
computer 42, and the operations are controlled by such a sequence
as illustrated in the flow chart of FIG. 5.
[0061] If there are a plurality of wide-angle photographing
apparatus, at Step S501 the control program in the personal
computer 42 designates first a particular wide-angle photographing
apparatus by which images are desired to be displayed. At Step S502
an image request signal is transmitted via the network line 41 to
the designated wide-angle photographing apparatus. This image
request signal is received by the communication control circuit 38
of the designated wide-angle photographing apparatus, and the
communication control circuit instructs the system controller 37 to
transmit image pickup data of one frame of each of the cameras 11,
12 and 13 to the personal computer 42. The system controller 37
controls the memory control circuit 35, image encoding circuit 39
and communication control circuit 38 to transmit the encoded image
pickup data of each frame to the network line 41.
[0062] At Step S503 the personal computer 42 receives the encoded
image pickup data from the network line 41 and stores it in the
memory. At Step S504 the control program reads joining position
information of the photographed images of the cameras 11, 12 and 13
from a reference table. At Step S505 the image pickup data of
frames of the cameras is decoded and synthesized in accordance with
the joining position information, and displayed on the image
display window. In this case, the identification number added to
each image pickup data is read, and the image pickup data is
displayed being juxtaposed on the image display widow at
predetermined positions in accordance with the identification
numbers.
[0063] Next, at Step S506 while viewing the images, the observer
can adjust the joining positions of the images by using the
adjustment buttons to continuously join the images of the object at
the boundaries of the images of the cameras. The joining position
information is stored in the reference table to update it, so that
the photographed images are displayed in accordance with the
updated joining position information.
[0064] The image request signal is sent to the wide-angle
photographing apparatus to acquire the next image pickup data and
display it on the image display window to update it. This operation
is repeated by the control program until a stop instruction is
issued from a user by operating a reception OFF.
[0065] With the arrangement described above, an image of a
wide-angle in the horizontal direction can be obtained, and a
uniform and high resolution can be obtained because a plurality of
image pickup devices are used.
[0066] In the above description, photographed images 201, 202 and
203 sent from the wide-angle photographing apparatus are displayed
without particular image processing. However, in order to obtain a
more-seamless panorama image, a general image distortion correction
process of generating a panorama image may be executed. For
example, the photographed images may be subjected to a distortion
correction process of projecting the images on a cylindrical
surface and displaying the images in a juxtaposed state to thereby
convert the images into a panorama image as viewed from the center
of curvature of the cylinder. A trapezoid correction may be
performed for the photographed images 201 and 203 on opposite sides
to convert them into an image projected on the same flat plane as
the image pickup plane of the center camera 12 as, thereby
providing a panorama image viewed from the camera 12.
[0067] Such distortion correction processes may be executed by the
control program of the personal computer 42 or by the image signal
processing circuit of the wide-angle photographing apparatus.
[0068] In this embodiment, although three cameras are disposed, two
cameras may be disposed as shown in FIG. 6. The optical axes of
cameras 11 and 12 cross at a cross point 5 on the object side and
are disposed at a shortest base line length of the cameras. It is
therefore possible to reduce a parallax amount on the boundary of
the photographed images and obtain a panorama image without any
practical problem.
Second Embodiment
[0069] FIG. 7 is an illustrative diagram of a camera layout
according to the second embodiment of the present invention. In the
first embodiment, although the cameras are disposed along the
horizontal direction, in the second embodiments cameras 71 are
disposed along both the horizontal and vertical directions in such
a manner that the optical axes of the cameras cross at one cross
point 5 on the object side.
[0070] FIG. 8A is a front view of the second embodiment in which
the cameras 71 are disposed in a matrix form. FIG. 8B is a cross
sectional view taken along line 8C-8C in FIG. 8A and FIG. 8B is a
cross sectional view taken along line 8B-8B in FIG. 8A. In the
8C-8C cross sectional view of FIG. 8B, the optical axes of the
cameras cross at the cross point 5, and the photographing field
angle along the horizontal direction is in the range indicated by
an arrow 75. In the 8B-8B cross sectional view of FIG. 8C, the
optical axes of the cameras cross at the cross point 5, and the
photographing field angle along the vertical direction is in the
range indicated by an arrow 76.
[0071] With this arrangement, the whole photographing view field is
a broad area of generally a semisphere shape so that a broad area
can be photographed. The apparatus can be made more compact than a
conventional radial layout of cameras. Since the cameras are
disposed at a shortest base line length of the cameras, it is
possible to narrow the area where an object is photographed
duplicately near the boundary of photographed images of the
cameras, and thus to obtain an image whose joining portion is not
conspicuous.
[0072] The structure and operation of the wide-angle photographing
apparatus of the second embodiment can be the same as those of the
first embodiment.
Third Embodiment
[0073] FIG. 9 is an illustrative diagram of the third embodiment of
the present invention. If the wide-angle photographing apparatus is
used for monitoring, it is necessary to photograph an object having
a low illuminance, such as in the night. Generally, a camera using
image pickup devices such as CCD photographs an object by setting
an infrared cut filter just above the image pickup device in the
day, and not by setting the infrared cut filer in a low
illuminance.
[0074] In the wide-angle photographing apparatus of the third
embodiment, mounted in a housing 83 are cameras 11 and 12 disposed
in such a manner that the optical axes cross at a cross point 5
similar to the first embodiment. An opening 80 for camera lenses is
formed through the housing 83, and an infrared cut filter substrate
81 is supported inside the housing to be slidable relative to the
opening by an unrepresented drive mechanism. For example, the drive
mechanism may have the structure that a movable member for holding
the infrared cut filter substrate 81 is supported by a slide shaft
and a screw mounted on the shaft of a motor, and when the motor is
driven, the infrared cut filter substrate can be moved along an
arrow direction.
[0075] An infrared cut filter is formed in an oblique line portion
82 of the infrared cut filter substrate 81, and the other portion
is a transparent substrate without an infrared cut filter. By
sliding the infrared cut filter substrate along the arrow direction
by the drive mechanism, the states with and without the infrared
cut filter can be switched.
[0076] In this embodiment, by disposing the filter near the cross
point of the optical axes of a plurality of cameras and switching
the filter, the filter of the cameras can be switched at the same
time so that the wide-angle photographing apparatus can be
manufactured in a compact size and with a low cost.
[0077] The object of the present invention can be achieved also by
providing a wide-angle photographing apparatus with a storage
medium storing software program codes realizing the functions of
the above-described embodiments and making the wide-angle
photographing apparatus execute the program codes. In this case,
the program codes read from the storage medium realize the
embodiment functions so that the storage medium storing the program
codes constitutes the present invention.
[0078] The storage medium for storing such program codes may be a
ROM, a flexible disk, a hard disk, a magneto optical disk, a
CD-ROM, a CD-R, a memory card and the like. The hardware and
software structure of the above-described embodiments may be
replaced with a structure realizing similar functions to those of
the embodiments.
[0079] The present invention has been described in connection with
the preferred embodiments. The present invention is not limited to
the above-described embodiments, but various alterations are
possible without departing from the scope of claims.
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